Podoplanin Immunopositive Lymphatic Vessels at the Implant Interface in a Rat Model of Osteoporotic Fractures
Figure 2
Podoplanin immunohistochemical staining in the rat osteoporotic fracture model.
The 3 mm (A) defect was narrowed by new built bone (b) but the remaining granulation tissue (gt) contains a high number of lymphatic vessels (arrow in B). Podoplanin positive osteocytes are localized in the new built bone (C). The 4 mm defect (D) is a typical critical size defect showing no bridging of the fracture gap that was filled with granulation tissue (gt) with only a few lymphatics (arrow in E-F) but a lot of blood vessels (stars). The vasculature was identified by Microfil® perfusion (stars in D-F), immunohistochemistry for CD31 (inset in E), anatomical characteristics (F), and their absence of podoplanin immunreaction (F). The fracture gap of the 5 mm defect (C) was filled with granulation tissue (gt) that contained a high amount of lymphatic vessels (arrow) but only limited blood vessels. Higher magnification of lymphatics showed the irregular shape, the discontinuous endothelium, and thin walls in comparison to the thick muscle layer in the walls of arteries (Ar) and continuous endothelium and wider lumen of veins (V in F). The nuclei were counterstained with hematoxylin. Bar: 1 mm in A, D, G, 200 µm in B, E, H, 20 µm in C, F and inset in E.